The overall purpose of the CAPS Policy and Ethics Core is to assure that HIV prevention and policy research at CAPS meets the highest ethical standards, addresses pressing policy questions, and has a high impact on the policy-making process. The Core provides consultation and technical assistance to prevention scientists on how to resolve the ethical dilemmas that inevitably arise in HIV prevention research and on how to increase the policy impact of their research. Moreover, this core supports research on such urgent topics as addressing ethical concerns about HIV prevention trials in resource-poor countries and evaluating a new state program for HIV surveillance using non-name codes. Because of the evolution of the epidemic, we will focus on addressing dilemmas in HIV prevention research and services caused by gaps in resources between developed and developing nations, evaluating the impact of policy changes, and improving the oversight of prevention research. Policy and ethics are addressed in a single unit to provide administrative efficiency and intellectual synergy.